def curl(f, dx, dy, dz, run2D=False):
"""
Take the curl of a pencil code vector array.
The run2D parameter deals with pure 2-D snapshots (solved the (x,z)-plane pb).
"""
import numpy as np
from pencilnew.math.derivatives.der import xder, yder, zder
if (f.shape[0] != 3):
print("curl: must have vector 4-D array f[3,mz,my,mx] for curl.")
raise ValueError
curl_value = np.empty_like(f)
if (dy != 0. and dz != 0.):
# 3-D case
curl_value[0, ...] = yder(f[2, ...], dy) - zder(f[1, ...], dz)
curl_value[1, ...] = zder(f[0, ...], dz) - xder(f[2, ...], dx)
curl_value[2, ...] = xder(f[1, ...], dx) - yder(f[0, ...], dy)
elif (dy == 0.):
# 2-D case in the xz-plane
curl_value[0, ...] = zder(f, dz, run2D)[0, ...] - xder(f, dx)[2, ...]
else:
# 2-D case in the xy-plane
curl_value[0, ...] = xder(f, dx)[1, ...] - yder(f, dy)[0, ...]
return curl_value
def div(f, dx, dy, dz):
"""
Take divervenge of pencil code vector array f.
"""
from pencilnew.math.derivatives.der import xder, yder, zder
if (f.ndim != 4):
print("div: must have vector 4-D array f[mvar ,mz, my, mx] for divergence.")
raise ValueError
return xder(f[0, ...], dx) + yder(f[1, ...], dy) + zder(f[2, ...], dz)
def curl2(f, dx, dy, dz):
"""
Take the double curl of a pencil code vector array f.
CARTESIAN COORDINATES ONLY!!
"""
import numpy as np
from pencilnew.math.derivatives.der import xder, yder, zder, xder2, yder2, zder2
if (f.ndim != 4 or f.shape[0] != 3):
print("curl2: must have vector 4-D array f[3,mz,my,mx] for curl2.")
raise ValueError
curl2_value = np.empty(f.shape)
curl2_value[0, ...] = xder(yder(f[1, ...], dy) + zder(f[2, ...], dz), dx) \
-yder2(f[0, ...], dy) - zder2(f[0, ...], dz)
curl2_value[1, ...] = yder(xder(f[0, ...], dx) + zder(f[2, ...], dz), dy) \
-xder2(f[1, ...], dx) - zder2(f[1, ...], dz)
curl2_value[2, ...] = zder(xder(f[0, ...], dx) + yder(f[1, ...], dy), dz) \
-xder2(f[2, ...], dx) - yder2(f[2, ...], dy)
return curl2
def grad(f, dx, dy, dz):
"""
Take the curl of a pencil code scalar array f.
"""
import numpy as np
from pencilnew.math.derivatives.der import xder, yder, zder
if (f.ndim != 3):
print("grad: must have scalar 3-D array f[mz, my, mx] for gradient.")
raise ValueError
grad_value = np.empty((3,) + f.shape)
grad_value[0, ...] = xder(f, dx)
grad_value[1, ...] = yder(f, dy)
grad_value[2, ...] = zder(f, dz)
return grad_value